* First step in Flutter Doctor refactor. Assigns categories to all validators.
* Revert "Roll engine e54bc4ea1832..a84b210b3d26 (6 commits) (#20453)"
This reverts commit 05c2880a17.
* Split iOS and Android workflows into workflow and validator classes.
* Change ValidatorCategory to handle standalone validators that share a
category (e.g. IntelliJ).
Also make Android Studio and Android toolchain use separate categories.
At this stage, flutter doctor output matches what it was previously.
(The summary() method itself has not yet been changed )
* Change doctor summary code to support validator categories.
Output is still unchanged.
* Handle small formatting issues.
* Flip Flutter category's isGroup field to false until it's actually
needed.
* Revert auto-generated formatting changes to keep those lines from
muddying the pull.
* Small fixes pointed out by analyzer.
* Properly fix analyzer issues around const constructors.
* Small changes to address comments.
* Add tests to verify grouped validator behavior and validationtype
merging.
* Update doctor.dart
* Add comments for clarification.
All temporary directory start with `flutter_` and have their random component separated from the name by a period, as in `flutter_test_bundle.YFYQMY`.
I've tried to find some of the places where we didn't cleanly delete temporary directories, too. This greatly reduces, though it does not entirely eliminate, the directories we leave behind when running tests, especially `flutter_tools` tests.
While I was at it I standardized on `tempDir` as the variable name for temporary directories, since it was the most common, removing occurrences of `temp` and `tmp`, among others.
Also I factored out some common code that used to catch exceptions that happen on Windows, and made more places use that pattern.
* Upgrade everything except matcher.
* Roll matcher (and test)
* Adjust tests that depend on flutter:test directly to depend on a shim
* Require use of package:test shim and remove other references to package:test
* Revert "Revert "Add android license verification to doctor and some refactoring" (#14727)"
This reverts commit d260294752.
* Add tests, fix sdkManagerEnv and use it consistently, and rearrange Status object model
* AnsiSpinner needs to leave the cursor where it found it.
* fix tests
* Const constructor warning only shows up on windows...?
* Avoid crash if we can't find the home directory
* Make pathVarSeparator return a string in the mock
* Implement review comments
* Fix out-of-order problem on stop
Reports from that commit included:
* Doctor hanging
* Doctor prompting to install JDK
* AnsiStatus.cancel() printing elapsed time and extra newline
* Printing extra spinner character at the end of each line
* Initial version, seems to work
* Unit test for android license checker
* Cleanups
* Windows analyzer wants const.
* Refinements to timeout
* review comments
* Forgot a nit
